1. Field of the Invention
The present invention relates to an apparatus and method for supporting a multiple antenna service in a wireless communication system. More particularly the present invention relates to an apparatus and method for supporting an adaptive multiple antenna service for adapting an antenna structure of a Mobile Station (MS) in a wireless communication system.
2. Description of the Related Art
Due to the rapid growth of the wireless mobile communication market, there is a demand for a variety of wireless multimedia services. Recent advancements make it possible to provide the multimedia services by transmitting large amounts of data at a high speed. However, while there is an increasing demand for the multimedia services, there are only limited frequency resources with which to provide those services. Accordingly, research on a multiple antenna system (e.g., a Multiple Input Multiple Output (MIMO) system) is being conducted to more efficiently utilize the limited frequency resources.
The multiple antenna system transmits data using channels that are independent from each other on an antenna by antenna basis. Thereby, the multiple antenna system can increase transmission reliability and a data rate compared to a single antenna system without allocating additional frequencies or transmission power.
The multiple antenna system utilizes a different transmission/reception method depending on if it is supporting a single user or multiple users. In addition, the transmission/reception method is different depending on if a transmitting end of the multiple antenna system recognizes channel information for a receiving end.
In order to provide a multiple antenna service in a wireless communication system, a transmitting end and a receiving end include multiple antennas. The multiple antennas have to maintain more than a constant distance (e.g., λ (wavelength length)/4). That is, when the transmitting/receiving ends include multiple antennas and the multiple antennas have the same signal incident angles and positions as the signal distributors, the multiple antennas experience poor performance as a result of interference between the antennas, if the antennas are positioned too close to each other to achieve a space correlation between the antennas. Thus, when the multiple antennas are provided in the wireless communication system, each antenna has to maintain more than a minimum distance from the other antenna.
However, a Mobile Station (MS) of the wireless communication system is constructed to be small for easy portability. Thus, when the MS has multiple antennas, there is a problem in that the MS experiences poor performance due to interference between the antennas since the MS cannot provide a sufficient distance for a space correlation between the multiple antennas.